Write a short note on Bt cotton. A simple answer would help!!!!
Bt cotton is genetically modified form of cotton which is resistant to the common pests of cotton like moths, beetles, flies. Bt cotton contains the gene for Bt toxin which is a toxin produced by the bacteria Bacillus thuringiensis. Hence, Bt cotton produces this toxin which is harmful to the pest but not harmful for other organisms. On consumption of the plant parts, the insects ingest toxins which create pores in the stomach of insects resulting in death.
Therefore, Bt cotton is a plant which produces natural pesticides and helps in reduction in the use of chemical pesticides in cotton fields.
The Bt cotton variety contains a foreign gene obtained from bacillus thuringiensis. This bacterial gene, introduced genetically into the cotton seeds, protects the plants from bollworm (A. lepidoptora), a major pest of cotton. The worm feeding on the leaves of a BT cotton plant becomes lethargic and sleepy, thereby causing less damage to the plant. Field trials have shown that farmers who grew the Bt variety obtained 25%–75% more cotton than those who grew the normal variety. Also, Bt cotton requires only two sprays of chemical pesticide against eight sprays for normal variety.